Examples of conventional image display apparatus include cathode ray tubes, liquid crystal panels and a plasma displays. In general, a cathode ray tube has a curved-shaped image display screen. However, a cathode ray tube having a flat image display screen which provides an image display with high resolution and less distortion over the whole screen are used as computer displays and the like. Many of the front panels which are layered on the flat panel through an adhesive resin layer serve not only a reinforcement function for the image display screen but also an anti-reflection function against outside light and an anti-static function. In general, an image display apparatus having multilayer structure comprising a flat panel, an adhesive resin layer and a front panel is manufactured as follows. First, spacers are placed at a flat panel portion, a front panel is placed on the flat panel, and the gap at the periphery between the flat panel and the front panel is sealed by using resin tape or resin for sealing having a high viscosity. The gap at the periphery between the image display screen and the front panel is filled by injecting adhesive resin having a low viscosity from an opening that is formed in the periphery of the flat panel and the front panel. Then, the adhesive resin is hardened, and as a result, an image display apparatus having multilayer structure comprising a flat panel, an adhesive resin layer and a front panel is manufactured. (For example, refer to Japanese Un-examined Patent Publication NO. Hei 6-20598.)
However, the above-mentioned manufacturing method has following problems and is required to be improved.
First, in a method for sealing a gap between the flat panel and the front panel by using a resin for sealing having a high viscosity, a step of hardening resin by irradiating ultraviolet rays or heating that usually needs 30 to 90 minutes is required twice for the sealing-resin and the adhesive resin.
Second, in sealing, the image display screen has to be maintained horizontally. However, in injecting adhesive resin in a gap at the periphery between the flat panel and the front panel, the image display screen has to be tilted. Therefore, in attaching the front panel to the flat panel of the image display apparatus, two kinds of structures, maintaining the image display apparatus horizontally and maintaining the image display apparatus in a position tilted at a certain angle are required.
On the other hand, in a method for sealing a gap at the periphery between the flat panel and the front panel by using resin tape, sealing is not completed sufficiently, and the adhesive resin might leak out before hardened.
In addition to that, there are the following problems concerning production efficiency that apply to both of the above-mentioned methods. First, it takes a long time to inject adhesive resin in a narrow gap that is formed between the flat panel and the front panel. Second, bubbles are easily formed in the adhesive resin layer. Third, control of the viscosity of the resin is required strictly for the resin to be filled completely in the whole area.